Michelle Chatwin

Dr. Michelle Chatwin

1. Royal Brompton Hospital, Sydney St, London SW3 6NP, UK
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Research Focus & Metrics

Academic Career Length

19Years (2008-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 March 2018 in Respiratory Medicine
Verified
Journal Article
Open access
MCMichelle Chatwin
Michelle Chatwin
MTMichel Toussaint
Michel Toussaint
MGMiguel R. Gonçalves
Miguel R. Gonçalves
NSNicole Sheers
Nicole Sheers
UMUwe Mellies
Uwe Mellies
BMBrenda M. Morrow
Brenda M. Morrow
This is a unique state of the art review written by a group of 21 international recognized experts in the field that gathered during a meeting organized by the European Neuromuscular Centre (ENMC) in Naarden, March 2017. It systematically reports the entire evidence base for airway clearance techniques (ACTs) in both adults and children with neuromuscular disorders (NMD). We not only report randomised controlled trials, which in other systematic reviews conclude that there is a lack of evidence base to give an opinion, but also include case series and retrospective reviews of practice. For this review, we have classified ACTs as either proximal (cough augmentation) or peripheral (secretion mobilization). The review presents descriptions; standard definitions; the supporting evidence for and limitations of proximal and peripheral ACTs that are used in patients with NMD; as well as providing recommendations for objective measurements of efficacy, specifically for proximal ACTs. This state of the art review also highlights how ACTs may be adapted or modified for specific contexts (e.g. in people with bulbar insufficiency; children and infants) and recommends when and how each technique should be applied.

1 October 2010 in Health Technology Assessment
Verified
Journal Article
Open access
PDF file
ASAk Simonds
Ak Simonds
AHA Hanak
A Hanak
MCMichelle Chatwin
Michelle Chatwin
MMMj Morrell
Mj Morrell
AHA Hall
A Hall
RDRj Dickinson
Rj Dickinson
Background Influenza viruses are thought to be spread by droplets, but the role of aerosol dissemination is unclear and has not been assessed by previous studies. Oxygen therapy, nebulised medication and ventilatory support are treatments used in clinical practice to treat influenzal infection are thought to generate droplets or aerosols. Objectives Evaluation of the characteristics of droplet/aerosol dispersion around delivery systems during non-invasive ventilation (NIV), oxygen therapy, nebuliser treatment and chest physiotherapy by measuring droplet size, geographical distribution of droplets, decay in droplets over time after the interventions were discontinued. Methods Three groups were studied: (1) normal controls, (2) subjects with coryzal symptoms and (3) adult patients with chronic lung disease who were admitted to hospital with an infective exacerbation. Each group received oxygen therapy, NIV using a vented mask system and a modified circuit with non-vented mask and exhalation filter, and nebulised saline. The patient group had a period of standardised chest physiotherapy treatment. Droplet counts in mean diameter size ranges from 0.3 to > 10 µm were measured with an counter placed adjacent to the face and at a 1-m distance from the subject/patient, at the height of the nose/mouth of an average health-care worker. Results NIV using a vented mask produced droplets in the large size range (> 10 µm) in patients (p = 0.042) and coryzal subjects (p = 0.044) compared with baseline values, but not in normal controls (p = 0.379), but this increase in large droplets was not seen using the NIV circuit modification. Chest physiotherapy produced droplets predominantly of > 10 µm (p = 0.003), which, as with NIV droplet count in the patients, had fallen significantly by 1 m. Oxygen therapy did not increase droplet count in any size range. Nebulised saline delivered droplets in the small- and medium-size aerosol/droplet range, but did not increase large-size droplet count. Conclusions NIV and chest physiotherapy are droplet (not aerosol)-generating procedures, producing droplets of > 10 µm in size. Due to their large mass, most fall out on to local surfaces within 1 m. The only device producing an aerosol was the nebuliser and the output profile is consistent with nebuliser characteristics rather than dissemination of large droplets from patients. These findings suggest that health-care workers providing NIV and chest physiotherapy, working within 1 m of an infected patient should have a higher level of respiratory protection, but that infection control measures designed to limit aerosol spread may have less relevance for these procedures. These results may have infection control implications for other airborne infections, such as severe acute respiratory syndrome and tuberculosis, as well as for pandemic influenza infection.

1 May 2015 in PLOS ONE
Verified
Journal Article
Open access
PDF file
MCMichelle Chatwin
Michelle Chatwin
HTHui-Leng Tan
Hui-Leng Tan
ABAndrew Bush
Andrew Bush
MRMark Rosenthal
Mark Rosenthal
ASAnita Kay Simonds
Anita Kay Simonds
The number of children receiving domiciliary ventilatory support has grown over the last few decades driven largely by the introduction and widening applications of non-invasive ventilation. Ventilatory support may be used with the intention of increasing survival, or to facilitate discharge home and/or to palliate symptoms. However, the outcome of this intervention and the number of children transitioning to adult care as a consequence of longer survival is not yet clear. In this retrospective cohort study, we analysed the outcome in children (<17 years) started on home NIV at Royal Brompton Hospital over an 18 year period 1993-2011. The aim was to establish for different diagnostic groups: survival rate, likelihood of early death depending on diagnosis or discontinuation of ventilation, and the proportion transitioning to adult care. 496 children were commenced on home non invasive ventilation; follow-up data were available in 449 (91%). Fifty six per cent (n=254) had neuromuscular disease. Ventilation was started at a median age (IQR) 10 (3-15) years. Thirteen percent (n=59) were less than 1 year old. Forty percent (n=181) have transitioned to adult care. Twenty four percent (n=109) of patients have died, and nine percent (n=42) were able to discontinue ventilatory support. Long term ventilation is associated with an increase in survival in a range of conditions leading to ventilatory failure in children, resulting in increasing numbers surviving to adulthood. This has significant implications for planning transition and adult care facilities.

23 June 2010 in Archives of Disease in Childhood
Verified
Journal Article
Closed access
PDF file
MCMichelle Chatwin
Michelle Chatwin
ABA. Bush
A. Bush
ASA. K. Simonds
A. K. Simonds
Background There are widely discrepant views on the respiratory management of infants with spinal muscular atrophy (SMA) type I. Typically, management is palliative. Design A descriptive study of interventions and investigations is reported that were offered to a cohort of 13 children with SMA type I referred to our centre. Interventions and investigations included sleep studies, provision of non-invasive positive pressure ventilation (NIPPV) for ventilatory support/dependency and for physiotherapy and the use of mechanical insufflation/exsufflation (MI-E). Results NIPPV was provided for the following indications: continuous positive airways pressure flow driver dependency (n=3), nocturnal hypoventilation (n=3), to enable successful extubation (n=2), in anticipation of respiratory decompensation (n=3), and oxygen dependency/decompensation (n=2). NIPPV and MI-E were used for successful protocol-led extubations (n=9) but not non protocol-led successes (n=3). NIPPV was essential for discharge home in patients with ventilatory dependency (n=7) and was used for palliation of respiratory symptoms (n=4). Chest wall shape improved with NIPPV. The parents of children who died (n=5) were positive about the use of these techniques. Conclusion NIPPV can be used to facilitate discharge home, and MI-E is helpful in this group. This symptom and goal-directed approach can be used to inform medical decision making and to help parents make informed choices about the appropriateness of respiratory interventions in SMA type I.

5 November 2019 in Respiratory Care
Verified
Journal Article
Closed access
PDF file
MCMichelle Chatwin
Michelle Chatwin
ASAnita K Simonds
Anita K Simonds
BACKGROUND: Mechanical insufflation-exsufflation (MI-E) devices increase expiratory air flow and thereby promote increased cough peak flow (CPF) in conjunction with a cough. There is little research looking at long-term use of MI-E in subjects with neuromuscular disease (NMD), and no long-term study has reported CPF, MI-E device settings, and adherence. METHODS: We evaluated 181 patient records (130 adults, 51 children) of individuals who received a MI-E device from our center between February 2014 and February 2018. Median age (interquartile range [IQR]) was 27 (14–51) y. Duchenne muscular dystrophy (DMD), spinal muscular atrophy (SMA), and amyotrophic lateral sclerosis (ALS) were the 3 most common diagnoses. RESULTS: MI-E devices were provided to the weakest subjects with a CPF < 160 L/min. Median (IQR) settings were insufflation, 25 (23–30) cm H 2 O, exsufflation −35 (−30 to −40) cm H 2 O, insufflation time 1.5 (1.3–1.7) s, exsufflation time 1.8 (1.5–2.0) s, and pause 1.5 (1.3–2.0) s. The inspiratory flow profile was set to high in all subjects, and no subject used supplemental oxygen with the MI-E device. When comparing insufflation pressures to exsufflation pressures, a greater negative pressure was used relative to positive pressure ( P < .001). When comparing insufflation to exsufflation time, there was a significantly longer exsufflation duration ( P < .001). Median (IQR) CPF at the start of MI-E was 60 (10–100) L/min. There was no correlation between either insufflation or exsufflation pressures and CPF. Median (IQR) usage for the group was 60% (13.5–100%) of days for the total days. Subjects with tracheostomies or SMA type I had the greatest adherence to treatment. Median (IQR) duration of MI-E use was 17 (8.5–32) months. Ninety-six percent of subjects were receiving ventilatory support. CONCLUSIONS: Greater exsufflation pressures than insufflation pressures, together with a shorter insufflation time than exsufflation time, were used. Predicting good adherence among the subjects was difficult. Subjects who produced daily secretions were more likely to use MI-E every day.

1 November 2008 in Respiratory Medicine
Verified
Journal Article
Closed access
MCMichelle Chatwin
Michelle Chatwin
ANAnnabel H. Nickol
Annabel H. Nickol
MMMary J. Morrell
Mary J. Morrell
MPMichael I. Polkey
Michael I. Polkey
ASAnita K. Simonds
Anita K. Simonds